Law360, New York (August 25, 2004, 12:00 AM EDT) -- Antitrust regulators with the European Union have ordered an in-depth investigation into a deal between Microsoft Corp. and Time Warner Inc. to collaborate on a project to make anti-piracy software.

The European Commission Wednesday opened a four-month investigation into plans by two U.S. companies, respectively the world’s largest software maker and the U.S. largest media company, over their plans for ContentGuard Inc.

Last April, Time Warner joined Microsoft, an existing investor, to buy most of Xerox Corp.'s ownership of Maryland-based ContentGuard. Other partners include Japanese giant...